JPS62179032A - Loop checking system for program - Google Patents

Abstract

PURPOSE:To detect the scope of the abnormal loop of a program without fail and rapidly without troubling a person by inspecting the tracing data obtained by the branch success tracing function of a service processor. CONSTITUTION:A service processor 3 decides whether or not the branch is a success, and has at least a branch success tracing part 3b to store the address data when the branch is the success, into a tracing area 3a, and an information processing part 3d to execute the input output processing, etc., of the information from a central processing unit 1 by using a work area 3c. The branch success tracing processing part 3b is constituted of a branch success tracing function and an abnormal loop checking means to execute the arithmetic processing at the time of the occurrence of the abnormal loop and detect the abnormal loop. By the branch success tracing function of such a service processor 3, it is inspected whether or not the same executing route is repeated, and in case the route is repeated, the abnormal loop is decided and the scope is displayed, for example, at the display device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a program loop check method for debugging a program using a service processor provided for operating and maintaining a computer.

[Conventional technology]

Generally, in the software development process, an abnormal loop in a program running in a problem program mode or an abnormal loop in a range spanning multiple programs may occur at a stage after an integration test.

When this abnormal loop occurs, conventionally the range of the abnormal loop has been narrowed down from the range of instruction addresses obtained by repeatedly stopping and starting the computer.

[Problem that the invention seeks to solve]

However, the conventional program abnormal loop check method described above has the problem that accurate information cannot be obtained depending on the timing at which the computer is stopped, and it also requires too much manpower.

Therefore, it is possible to detect the occurrence of abnormal loops using the program depacking function of the service processor.
Its debug functions include the following:

a) Loop detection handler (LoopD
(hereinafter referred to as LDH) b) iC) Race C) Branch success trace However, the LDH in item a) is a function that monitors a program that runs in supervisor mode without waiting for a certain period of time, and is It cannot be applied to detecting abnormal loops.

In addition, in the case of 1C1-race in item b) above, there still remains the problem that the limitation of the trace area is a fatal problem because it is traced for each instruction, and that it requires a lot of manual work. .

Furthermore, in the branch success trace in section C) above, considering that both loops within a program and loops spanning multiple programs branch from the same address, abnormal loops However, it has the same problems as in item b) above, except that the restrictions on the trace area are relaxed.

Therefore, the present invention has been made by focusing on the problems of the above-mentioned conventional example. An object of the present invention is to provide a program loop check method that can inspect the loop state and detect the loop range without manual work when an abnormal loop occurs.

[Means for solving problems]

In order to achieve the above object, the present invention allows a service processor attached to a computer and equipped with a branch success tracing function to detect the presence or absence of an abnormal loop by using the instruction address at the time of a successful branch obtained by the branch success tracing function. An abnormal loop check means is provided to check the possibility of an abnormal loop in the computer program.

[Effect]

In this invention, focusing on the fact that a normal program always has a branch point, the branch source address information obtained by the branch success trace function of the service processor is used to determine whether the same execution route is repeated or not. An abnormal loop in a program and its range are detected by inspecting the loop, determining that it is an abnormal loop when it is repeated, and displaying the range on, for example, a display device.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, ■ is the central processing unit, 2 is the central processing unit l
3 is a service processor connected to the output side of the central processing unit 1, and 4 is a display device connected to the service processor 3.

The service processor 3 includes a branch success trace processing unit 3b that determines whether or not the branch is successful and stores address data at that time in the trace area 3a when the branch is successful, and a branch success trace processing unit 3b that inputs and outputs information from the central processing unit 1. It is configured to include at least an information processing section 3d that performs processing and the like using a work area 3c.

The branch success trace processing section 3b is composed of a branch success trace function and an abnormal loop check means for detecting an abnormal loop by executing the arithmetic processing shown in FIG. 2 when an abnormal loop occurs.

That is, in step (2), the range of loop inspection is set.

In this case, the maximum inspection range MAX is set to 2, which is the number of traces that can be stored in the preset trace area 3a.

Next, the process moves to step (3), where a ranking setting variable m for setting the ranking of trace data to be searched is set to "0".

Next, the process moves to step (2), where a variable l representing the number of items searched within the loop range is set to "O", and a variable X representing a loop problem is set to "0".

Next, the process moves to step (2), and by setting the rank setting variable m to a value m+l, which is obtained by adding "l" to the rank setting variable m, it is set how many pieces of trace data before the current trace data is to be examined.

Next, the process moves to step (2), and it is determined whether or not the inspection range has been exceeded. In this case, the determination is made based on whether or not the rank setting variable m exceeds the maximum inspection range MAX.
If so, it is determined that the test range has been exceeded, and the process moves to step (2), where the display device 4 displays that the loop is not detectable because the loop is not looping or the loop is abnormal in the test range, and then the loop is resumed. Finish the inspection process.

On the other hand, if m≦MAX, it is determined that it is within the inspection range, and the process moves to step (2), where the trace data a of the pointer indicating the latest branch success trace data and the trace data currently being inspected (a- m) is equal to each other.

At this time, if a≠(a-m), the data of the pointer indicating the trace data does not match, and it is determined that no loop is formed, and the process returns to step (2).
When a=(a-m), it is determined that both data match and a loop is formed, and the process moves to step (2).

In this step (2), each element within the loop range is extracted. That is, the loop variable X indicating the loop fish is added by "1" and the data (a-β) is extracted as the loop X data.

Next, proceed to step ■, and set the inspection number variable l to "1".
” and then moves to step [phase], where it is determined whether all elements in the loop have been inspected. In this case, the determination is made by determining whether the number of inspection variables β is greater than or equal to the inspection order variable m. If l<m, it is determined that the inspection is in progress and the process moves to step 0.In this step It is determined whether the trace data currently being inspected is equal to the previous data (a-m-j2).At this time, both trace data (a-1),
When (a-m-1) do not match, it is determined that no loop is formed and the process returns to step (2), and when they match, the process returns to step (2).

Then, the determination result of step [phase] is l≧m,
When all the loop elements have been inspected, the process moves to step @, where the branch source addresses (loop (11 to loop (X)) existing in the loop range are displayed on the display device 4, and the loop inspection process ends. do.

Now, as shown in Figure 3, program A is (a
Assuming that an abnormal loop is formed in the range l, the branch success trace processing unit 3b executes the arithmetic processing shown in FIG. 2, and the branch success trace data stored in the trace area 3a at this time is referred to. Assuming that the latest trace data is address 1, in step ■ it is set to inspect the trace data (address 2) immediately before the latest trace data, and then in step ■, since m>MAX, , the process moves to step ■, and since there is a mismatch between the latest trace data (address l) and the trace data currently being inspected (address 2), the process returns to step ■, and the trace data two pieces before the latest trace data (address 1) is set to be inspected, and then passes through step ■ and moves to step ■, where the latest trace data (address 1) and the trace data currently being inspected (address 1) match, so there is an abnormal loop. It is determined that it has been formed, and the process moves to step (2).

In this step (2), the loop variable is added by "I" to make 6=1.

Next, move to step [phase] and! ! = l <
Since m = 2, it is determined that the inspection has not been completed and step 0 is performed.
1 from the latest trace data (address 1)
Since the previous trace data (address 2) matches the trace data (address 2) that is one trace before the currently inspected trace data (address 1), return to step ■ and set the loop variable X to 2. At the same time, data (a-1) (address 2) immediately before the latest data is set as loop (2), and then test variable 2 is set to 2 in step (2).

When the inspection variable l is set to 2 in this way, it becomes equal to the inspection order setting variable m (=2) set in step The branch source addresses (addresses 1 and 2) existing in are output to the display device 4 and displayed, and the process ends. Then, by checking the program location on the main storage device f2 based on addresses 1 and 2, it is possible to detect that the program A is in a loop.

Similarly, as shown in (b) in Figure 4, even when an abnormal loop spans multiple programs A-C, by executing the same process as above, the programs are included in the abnormal loop sequentially. By displaying the addresses 2, 1.7.6° 5.4.3 on the display device 4 and investigating the program location in the main storage device 2 in this state, the abnormal loop can be traced to program A-7 from addresses 1 to 7. It is possible to detect that the object is straddling C.

Note that even if control is transferred between programs via a supervisor program, this does not affect the idea of the present invention in any way.

[Effects of the Invention] As explained above, according to the present invention, the trace data obtained by the branch success trace function of the service processor is inspected to detect abnormal loops and their ranges, so that the program can be improved. An effect is obtained in that the range of the abnormal loop can be detected reliably and quickly without any manual effort.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an outline of an embodiment of the present invention;
FIG. 2 is a flowchart showing an algorithm for loop inspection, and FIGS. 3 and 4 are explanatory diagrams showing an example of abnormal loop range detection, respectively. In the figure, 1 is a central processing unit, 2 is a main memory, 3 is a service processor, 3a is a trace area, 3b is a branch success trace processing unit, 3c is a work area, 3d is an information processing unit, and 4 is a display device. be.

Claims (1)

[Claims] A service processor attached to the computer and equipped with a branch success trace function is provided with an abnormal loop check means for checking the presence or absence of an abnormal loop using the instruction address at the time of branch success obtained by the branch success trace function, A program loop check method, characterized in that a loop check means checks the possibility of an abnormal loop in the computer program.